Method of softening and purifying water.



No. 665,266. mermaA 1an. mor. w. TwEEnnALE. METHOD 0F SOFTENING AND PURlFY-ING WATER.

(Application med Aug. 24, 1899.)

(No Model.)

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Tu: Nanms paens 00 woran-mc Msmnmon, ov c No. 665,286. Patented 1an. l, |964. w. TwEEnDALE. METHOD 0F SOFTENING AND PURIFYING WATER.

(Application f led Aug. 24, 1899.)

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(No Model.)

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UNITED STATES PATENT EETCE.

WILLIAM TWEEDDALF., OF TOPEKA, KANSAS.

METHOD OF SOFTENING AND PURIFYING WATER.

SPECIFICATION forming part of Letters Patent N o. 665,286, dated January 1, 1901.

Application filed August 24:, 1899. Serial No. 728,363. (No specimens.)

To all whom t may oon/cern:

Be it known that I, WILLIAM TWEEDDALE, a citizen of the United States, residing at Topeka, in the county of Shawnee and State of Kansas, have invented a new and useful Method of Softening and Purifying Water, of which the following is a specification.

This invention relates to improvements in methods of softening and purifying Water, and more particularly to that class of methods involving chemical reaction; and it has for its object to combine chemical, electrical, and mechanical action to remove both the insoluble impurities and the normal soluble impurities, both organic and inorganic.

The invention consists in changing both the organic and inorganic substances in solution in the water to an insoluble state in suspension and then by coagulation and aggregation of these impurities to form a coagulum which, being precipitated, carries down all impurities, including bacteria.

Any suitable apparatus may be employed in connection with this method, and in the drawings there is shown an apparatus particularly designed for the softening and purifying of feed-water for steam-boilers.

In the drawings forming a portion of this specification, and in which similar numerals of reference designate corresponding parts in the several views, Figure 1 is an elevation showing two tanks or reservoirs, one of which is broken away to show the location and arrangement of the oxidizers, the water supply and outlet, the drain-pipe, and the air-inlet and automatic water cut-off. Fig. 2 is a detail view showing the oxidizers and their connection with the Water-supply pipe, one of said oXidizers being in elevation, one in section, and one partially in elevation and partially broken away, a portion also being shown in section. Fig. 3 is a plan view of Fig. 2, showing the complete oXidizers with the exception of one, which has its web and filling removed.

Referring now to the drawings, 5 and 6 represent two tanks which are similar in form and equipment, and a description of the contents of the tank 5 will apply to the contents of the tank 6. Leading to the tanks is a Water-supply pipe 7, having branches 8 and 9 entering the tanks 5 and 6 and above which they are provided with regulating-valves 10, which are adapted to be operated manually.

Within each tank and connected with the water-supply is a valve-casing l1, containing a iioat-valve having an operating-fioat 12, which is adapted to rise and fall with the water in the tank to regulate the flow or cut olf the liow of the water-supply.

Connected with the outlet end of the casing 11 is a pipe 13, which extends downwardly and along the base of the tank, where it includes T-connections 14:, connected with the bottoms of cylindrical casings 15, each of which has a perforated false bottom 17 disposed above the bottom thereof.

Within each casing and concentric therewith is disposed a spiral web 1S, the outer end of which is in contact with the inner face of the casing and the several convolutions of which are connected at their upper ends by a cross-piece 19, of metal. The casing and its web are made, preferably, of sheet-iron and form the cathode of an electric battery, of which the anode isa filling 20, of coke or other form of porous carbon, the coke lying between the different convolutions of the web and between the outermost convolution and the inner surface of the casing. Suitable collectors 21, having a plate connection 22, are inserted in the coke filling, and to the plates 22 are connected wires leading to the plate 19 of the succeeding casing, thus connecting the several oasings or batteries in series. The electrolyte is formed by the water within the tank, or rather by the water in its passage to the tank. A steam-operated injector 25 has a delivery-pipe 26, provided at its upper ends with branches having controlling-valves 27 and from which lead pipes 28, which enter the pipes 13 in a downward direction, said inj'ector being constructed on the principle of an injector commonly employed for supplying water to a steam-boiler and which acts to force a supply of air through the pipes 26 and 28 and into the pipe 13 in the direction of the flow through said pipe 13, the air passing, with the water,upwardly and th rough the oxidizers.

A drain-pipe 30, having controlling-valves, is provided for each tank, and in order to draw the water from the tanks an outlet-pipe 31, entering near the bottom of each tank, has an upwardly-directed connection 32, hav- IOO ing a iioat 33 at its upper end and swiveled to the pipe 3l, so that said connection may rise and fall under variations in the level of the water in the tank and may thus act to draw the water from a point near its surface.

Having thus described the form of apparatus, the method and its operation are as follows: Having by analysis ofthe Water, verified by direct experiment, ascertained the nature and amount of impurities in solution, I calculate the quantities ot' reagents required to render insoluble the various salts that are present in solution and to neutralize the acids or alkalies in thevolume of water which the reservoir is known to contain and put these quantities of reagents into the tank. The salts to be removed are usually lime, magnesia, and iron in the form of sulfate and carbonate, the presence of which cause hardness when used for washing, incrustation in steam-boilers, and often induce disease when used dietetically. There may also be added a suitable amount of aferric salt, as ferricchlorid, which by reaction with any hydrates present in or added to the water will result in a gelatinous ferrie hydrate, which aids mechanically the separation of impurities in suspension in the liquid. The reagents, the natures of which have been determined by the character of the impurities in the water, are added to the tank. If these impurities arein the form of bicarbonates of calcium and magnesium, the reagent employed may be calcium hydrate or sodium hydrate. If the calcium hydrate is used, the chemical combination of the calci um hydrate with a portion of the combined carbonic acid forms an insoluble carbonate of calcium or magnesium. The tank' is then lilled with water,wl1ich enters through the oxidizers comprising the casing l5, and at the same time air is forced into the pipe 13 and passes through the oxidizers with the water. During the passage of the water through the oxi dizers the agitation of the water by the air and the reaction of the oxygen of the air with the ferrie reagent, together with the galvanic action of the oxidizers, accomplishes a complete oxidation of the organic matter and the water emerges from the oxidizers practically free from the organic impurities in solution. As the waterenters the tank it is thoroughly mixed with the reagents in the tank under the in tluence of the head of the water andthe passage of air therethrough. At the same time the water is agitated by theinjected air. After completion of all the reactions to neutrality clay and perchlorid of iron are added and the Water is linally agitated. The result is the coagulation of the insoluble impurities,

followed by the aggregation of the insoluble matter forming a condensed mass. This condensed mass being precipitated by sedimentation falls to the bottom of the tank, carrying down with it all insoluble substances. Also the presence of the ferrie hydrate, as above described, not only assists in the coagulation, but the oxygen thereof combines with whatever organic mattei' may be presentand oxidizes it, the oxygen being replaced from the injected air.

Then the water is clear, it may be drawn oi from nearthe surface by the method above described.

It will of course be understood that anydesired reagents may be employed to secure the reactions of the different impurities and that these reagents will be varied in accordance with the nature of the material; also, it Will be understood that any desired apparatus for carrying out the several steps of this process may be employed.

Having thus described the invention, what I claim is- 1. The method of softening and purifying water, which consists i-n aci-ating the water; oxidizing the organic matter therein by galvanic action; rendering insoluble thel salts held in solution and neutralizing the acids and alkalies by means of chemical agents; effecting the coagulation of 'the insoluble iinpurities, the said water being kept in astate of agitation during each of the foregoing operations; precipitating the insoluble impu rities by sedimentation, thus causing them to sink in mass to the bottom yof the water, substantially as described.

2. The method of softening and purifying water, which consists in aerating the water; oxidizing the yorganic matter therein by galvanic action; rendering insoluble the salts held in solution and neutralizing the acids `and akalies by means of chemical agents; effecting the coagulation of the insoluble impurities by means of chemical agents; keeping the water in a state of agitation during each of the foregoing operations rby the passage of a current of air through it; precipitating the insoluble impurities by sedimentation, thus causing them to `sink in mass vto IOO IIC 

